1. Technical Field
The disclosure relates to voice over Internet protocol (VoIP), and particularly to a network device and method for establishing quality of service (QoS).
2. Description of Related Art
In VoIP applications, voice packets need to be transmitted over networks with little delay and stable flow. If networks cannot provide QoS, they cannot make sure stable transmission of voice packets, which results in poor communication quality. There are two ways to establish QoS: a caller sends QoS requests before sending session initiation protocol (SIP) invitations; or a callee establishes QoS after receiving an SIP invitation from a caller.
However, a session may not be established successfully, thus establishing QoS before successfully establishing a session may waste QoS resources.